Water-jet propulsion device for boats



Oct. 19, 1965 c. A. GONGWER 3,212,258

WATER-JET PROPULSION DEVICE FOR BOATS Filed Oct. 16, 1961 3 Sheets-Sheet 1 INVENTOR. CALVIN A. GONGWER A770 NE) Oct. 19, 1965 c. A. GONGWER 3,212,258

WATER-JET PROPULSION DEVICE FOR BOATS Filed Oct. 16, 1961 s Sheets-Sheet 2 E g I I 1 3 3 1 7 co 0 m a 0 Q !5 @9 1- 00 D D 0 l 2 I [0 LL T C U Q in as ,5! E 2| INVENTOR.

CALVIN A. GONGWER A TTOR/VE Y Oct. 19, 1965 c. A. GONGWER WATER-JET PROPULSION DEVICE FOR BOATS 3 SheetsSheet 3 Filed Oct. 16. 1961 AQ HMW 01 3 R m in m m N o R 02$ my E e m MA I W W mm m i: M C N\ mm o- QT mw M 2 B mm. 02 f? ATTORNEY United States Patent Ohio Filed Oct. 16, 1961, Ser. No. 145,407 Claims. '(Cl. 6035.54)

This invention relates to improvements in devices for propulsion through a fluid medium and has for its principal object to improve the starting and operating characteristics of water vehicles motivated by a jet stream of water.

Propeller driven marine power devices are limited in high propulsive energy by the occurrence of cavitation. This phenomenon is the vaporization of a liquid caused by the local pressure reduction due to dynamic actions. The result of cavitation is a cavity of water vapor forming and collapsing in random sequence thus causing erosion, vibration, and noise.

Numerous advances in the marine propulsion art have been suggested, for example, hydraulic jet propulsion in the form of a pump system scooping water into an inlet duct and directing the water through a rotating impeller that restricts it at the discharge orifice, which may be used to eliminate cavitation from the operation. One form of this pump system is described in my copending application, Serial No. 20,897, filed April 8, 1960, now abandoned.

The hydraulic propulsion mechanisms for Water craft have, despite many years of application, proven to be a relatively-ineffective driving agency for sport and commercial use. Some of the undesired effects are, for example, the complexity of reversing and throttling mechanisms, the requirement of priming the hydraulic pump before operation, and excessive drag and clogigng of the inlet scoop. Numerous attempts have been made in the field of hydraulic propulsion to apply this type of driving means to most sport and commercial water craft without apparent acceptance. Some of these efforts have, but with little success, overcome in part some of the shortcomings of the basic hydraulic propulsion devices.

In accordance with my present invention, I overcome much of the undesired effects of conventional hydraulic propulsion units. One feature of the present invention is a device for reversing or throttling th jet stream issued from the hydraulic pump by use of a movable gate which regulates or deflects the jet flow either rearward or through a pair of forwardly directed nozzles. The position of the gate may be varied between the open and closed positions for obtaining a neutral inching forward, or inching backward movement. Another feature of the invention is an inducer attached to the drive shaft which provides an automatic priming device for the pump and supplies cooling water for the prime mover. Yet another feature is an inlet scoop for the hydraulic pump which substantially reduces drag upon the water craft and acts to deflect all foreign matter from the inlet, thus eliminating a continual cleansing problem.

Briefly, the invention relates to a hydraulic pump having a rotatable inducer attached to the pump driving shaft. A pivotal gate may be moved in a direction re ducing the pump jet stream directed rearwardly. When the gate is positioned in a closed position, the gate directs all of the jet stream through a pair of forwardly extending exhaust nozzles, thus reversing the direction of the water craft. The scoop has a particular configuration which streamlines the waterfiow past the inlet and has provisions for a deflecting means to prevent foreign material from being sucked into the pump.

Other features and advantages not specifically enumerated above will be apparent after consideration of the 3,212,258 Patented Oct. 19, 1965 following detailed description and the appended claims. The preferred form which the invention may assume is illustrated in the accompanying drawings in which:

FIG. 1 is a side elevational view of a propulsive unit embodying the present improvements, and which is operatively connected to and supported by the transom of an outboard motor boat;

FIG. 2 is a rear elevation of the propulsive unit such as shown in FIG. 1, with the transom of the boat, not shown;

FIG. 3 is a cross sectional view, partially shown in elevation, and taken along line 33 of FIG. 2; and

FIG. 4 is a cross sectional view of one of the reversing nozzles taken along line 44 of FIG. 1.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being carried out in various Ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring more particularly to the drawings, the numeral 1G designates the rear portion of a boat hull terminating in a transom 12. The present invention is a power device 14 which is attached to the transom 12 and extends outwardly from the boat hull 10 and arranged substantially above the plane of the bottom of the hull.

A prime mover (not shown), may be for example an internal combustion engine positioned within the hull 10 and attached to the power device 14 by a drive shaft 18 terminating in a U joint 20, the drive shaft 18 and the U joint 20 being shown in phantom lines in FIG. 3.

The entire power device 14 is attached to the transom 12 by a bracket 22 having a pair of journal bearings 24, 26 which provide points of support and a means for pivoting the entire power device 14. A plurality of bolts 28 lash the bracket to the transom 12.

The power drive 14 is composed of a radial flow pump 30, an impeller shaft 32 attached thereto, the housing 34 terminating in a scoop or water inlet member'36, and a reversing mechanism 38.

The housing 34, as illustrated in FIGS. 1 and 3, is comprised of a body 40, a scoop or inlet member 36, a bell housing 42, and a reversing gate 44. The body 40 has a pair of bosses 46 which extend rearwardly and are contiguously positioned with the bearings 24, 26, on the supporting bracket 22. Journal bearings 48, formed on the interior of the bosses 46, are axially aligned one with another and with the journal bearings 24, 26. A fiber washer 50 and bearing 52 are interposed between the body bosses 46 and one each side of the pivot pin 54. Snap. ring 56 and cotter pin 58, positioned on opposite sides of the pivot pin 54, prevent lateral movement. This arrangement allows the entire housing 34 and power device 14 to be pivoted by the tiller 60 which extends through the transom opening 62 and is attached to the uppermost portion of the housing body 40. Therefore, upon pivoting movement of the tiller 60, the housing 34 and the radial flow pump 30 pivot, similar to the action of a conventional outboard motor, for purposes of altering the course of the boat.

The impeller shaft 32 is splined at one end and is attached to the U joint 20 for transmittal of rotative power to the pump 30. Ball bearing 64 has its inner race slip fitted upon the portion of the impeller shaft 32 adjacent to the splined end thereof and has its outer race pressed into the recess 66 in the body 40. Seal 68 is pressed within the housing body opening 70 and bears against a raised portion of the impeller shaft 32, thereby sealing grease within the ball bearing 64 and preventing water from entering the bearing unit. An annulus shaped abutment 72 is retained against the housing body 40 by a plurality of machine screws passing therethrough. A second oil seal 74 is pressed into the abutment opening and bears against the impeller shaft 32, thereby sealing any oil or grease within the bearing unit.

A flexible boot 76 is positioned within the transom opening 78 and has a flange 80 which is forced against the interior of the transom by a clamp 82 which has a plurality of wood screws passing therethrough and engaging the transom. Boot 76 terminates in a nose projection 84 which extends over the body projection 86 and is retained thereby by the hose clamp 88. The boot 76 thereby prevents water and spray from entering the interior of the boat and still allows vibration and movement of the power device during operation.

The bell housing 42 is attached to the rearmost portion of the body 40 by a plurality of socket head cap screws 90 passing therethrough. A spider 92 is received within the bell housing 42, the spider. 92 including a radially outwardly extending flange 93 which is retained in clamped relation between the housing body 40 and an axially extending flange 94 on the bell housing 42 by the screws 90 passing through the bell housing 42 and threaded into the body 40, thereby securing the spider 92 against rotation. A journal bearing 95 is formed in the central portion of the spider 92 and supports the rearmost portion of the impeller shaft 32. A bearing insert may be used for replacement purposes. The radial flow pump 30 is retained upon the impeller shaft 32 by a key 96 and a castellated nut 98. The pump is a subject of the aforementioned copending application, Serial No. 20,897, filed April 8, 1860, now abandoned.

This pump 30 basically has an integrally rotated impeller 100, casing 102, and axially extending exhaust outlets 104 adapted for pumping water so as to discharge the water through the exhaust outlets 104 in a rearward, axially extending jet stream. One feature of this pump relates to the elimination of the stationary casing, since the impeller housing is integral with its casing and rotates as a unit, thereby reducing the water friction loss found when a stationary casing is present. The pump unit has an annulus shaped inlet passage 108 flaring outwardly and terminating in a plurality of exhaust nozzles 106. Sealing strap 110 prevents excessive water leakage from between the stationary spider 92 and rotatable pump casing 102. Hose clamp 112 retains the sealing strap 110 in position and is tightened upon the outer periphery of the spider 92. An annular sealing gasket 114 is carried by the spider 92, the gasket 114 being interposed between the stationary spider 92 and the rotatable pump unit housing 102.

The inducer 116, having a plurality of involute vanes thereon, is pressed upon the impeller shaft 32 adjacent the spider 92. Inducer 116 is used to increase the efficiency of the pump by forcing water into the pump inlet. The helicoidal shaped vanes tend to give water passing the inducer a helical motion which is corrected by the legs on the spider which are axially aligned with the impeller shaft axis. It should be noted that the spider legs perform a double function of supporting the journal bearing and correcting the swirl motion of the water caused by the inducer 116.

A plurality of curved vanes 118 are integrally formed within the housing body 40 and are positioned approximately intermediate of the pump unit and the housing inlet member. These vanes 118 function to divert water into the impeller 100 and henceforth into the pump unit and in effect cause the water to make a right angle turn as it progresses from the inlet to the pump unit.

Referring now to FIG. 3, the water inlet scoop 36 is bolted to the housing body flange 120 by a plurality of screws passing therethrough and threaded therein. The hollow scoop 36 has a passageway '122 therein which is formed contiguous with the housing body passageway 124. The scoop 36 is generally L shaped having its lower portion or nose 126 extending beneath the watercraft hull 10. Since the boat hull 10 generally rides below the surface of the water, the scoop 36 therefore skims water into the intake below the boat bottom and thereby prevents a greater majority of debris on the water surface from entering the power device 14.

A streamlined frontal inlet 128 on the scoop 36 provides an opening for the water to be rammed into the power device 14, thereby forcing proportionally more water into the inlet as the water craft gains speed. The vanes 130 are in spaced relation to each other and act as individual scoops to divert the water within the power device 14 and upwardly into the housing body. Vanes 130 are positioned at an angle A in relation to the boat bottom. A was found to be 22 /2", through empirical data for the most optimum operation at all speeds. Some of the problems to consider for the vane position are the drag of the vanes at high speeds, and the amount of water scooped by the vanes at low speeds without stalling the pump 30. It should be noted that the spacing between adjacent vanes has a tendency to prevent surface debris on the water from entering the power device and thereby acts as a screen 01' strainer.

Another feature of the present invention is the provisions of an annular collar 132 positioned between the housing body 40 and water inlet scoop 36 which is in sealing engagement therewith. Because the present in vention may be adapted to boats having transoms of varying height, the collar is used as the flexible component to compensate for the varied size of the boat. For example, collars of varied lengths may be stocked by the fabricator or dealer selling the subject power device, whereby the same size housing and inlet scoop may be used for many different size boats.

The fins 135, 137 mounted on opposite sides of the scoop 36, are another important feature in the present invention. As the boat hull 10 passes through water, a great amount of air is entrapped beneath the water surface due to agitation and cavitation. Because the inlet scoop 36 is constantly drawing water, entrapped air bubbles would tend to reduce the efficiency of the system. The laterally positioned fins tend to prevent the air bubbles from being sucked into the scoop. The combination of the nose 126 and fins 135, 137, all of which are positioned below the bottom of the boat, aid in preventing the air bubbles from following the contour of the scoop int-o the inlet.

A plurality of wires 134 acting as a means for deflecting debris are attached to the scoop nose 126 at the forward portion and trail substantially parallel to the scoop inlet 128.

As shown in FIGS. 1 and 3, a means for tapping water, such as the cooling water exhaust outlet 136, is integrally formed on the housing body 40. Although not illustrated, a conduit is attached to the exhaust outlet 136 and to the prime mover for cooling purposes. The advantage of this system is that once the power device is started, the region rearwardly of the inducer 116 is constantly under a positive pressure while the area immediately forward of the inducer is constantly under a vacuum thereby providing a constant source of cooling water to the prime mover. This cooling means eliminates special devices for siphoning water from beneath the boat hull that would create additional drag.

Referring now to FIGS. 1, 2, and 3, a means for deflecting the exhaust from the pump 30 is shown and may be for example the movable gate 44, which is illustrated in the up position. The gate 44 is basically hemispherical in configuration having its periphery finished to snugly mate with a comparable shaped area on the bell housing 42. By way of example, a gap of .006 inch is present between the bell housing 42 and gate 44 to allow for movement of the gate 44 without binding. A pair of reversing gate brackets 133, 140 are bolted to the opposite sides of the gate 44. Each of the brackets 138, 140 terminates at its extremity in a journal bearing 142 which has a commercial bronze bearing contained therein. The shoulder screw 144 threaded into the housing body 40, acts as a pivot point for each respective bracket 138, 149 of the reversing mechanism 38.

The hydraulic cylinder 146 of a commercial variety is pivotally attached to the forward portion of the gate 44 and also to the housing body. The coil spring 148 is attached to the arm 150 and to the housing 40. Thus the coil spring 148 tends to keep the reversing gate 44 in the up position as illustrated in FIGS. 13. The remaining mechanism for operating the hydraulic cylinder 146 is not shown, but is quite comparable to similar types of operating cylinders well known in the art. For example, a foot operated master cylinder (not shown) may be connected to the hydraulic cylinder in the manner similar to that used in the hydraulic brake system for most present day automobiles. In this manner, the master cylinder foot pedal may be depressed causing fluid to be forced into the hydraulic cylinder 146, thus forcing the piston rod 152 to be extended, and causing the gate to assume its closed position in which it completely covers the open end of the bell housing 42. Upon release :of pressure on the master cylinder pedal, the coil spring 148 then forces the gate back into its up position, as shown in FIGS. 1, 2, and 3. The reversing gate may be used either for throttling forward thrust developed from the pump device in reversing the boat or may be moved to any intermediate position to obtain a forward or reverse thrust of an intermediate degree.

As shown in FIGS. 1-3 and more especially in the cross section shown in FIG. 4, a pair of exhaust outlets 154, 156 are provided for the pump exhaust when the reversing gate 44 is in the down or closed position. It is noted that the exhaust outlets 154, 156 are formed with threaded nipples 158, 160 therein having nozzles formed therein. The thrust may be diverted at an angle in relation to the longitudinal axis of the boat by rotating the nipples within the outlets, since the nozzles are canted at an angle in relation to the outlets.

Following is a typical operation of the subject invention. In a static state, the boat hull 10 sits quite low in the water with the waterline approximately passing through the lower portion of the inducer. The reversing means 38 is lowered such that the gate 44 covers the bell housing opening and simultaneously the power source is started to cause the impeller shaft 32 to rotate. The inducer 116 forces water into the radial flow pump 30 thereby acting as a self-priming device. As the inducer sucks more and more water into the pump device, the pump exhaust is directed into the pair of exhaust outlets 154, 156 tending to first throttle the thrust of the power device, and as the pump is fully primed, the exhaust outlets will then produce thrust to reverse the boat. At this point, the operator has the option of either getting reverse thrust to direct the boat into open water or to open the reversing gate to allow the full thrust of the pump to be directed rearwardly, thus propelling the boat forwardly at a desired speed.

As the boat gains speed, the scoop vanes tend to ram a progressively larger amount of water into the housing body until the pump is operating at optimum efliciency. The wires 134- may tend to brush against the curved vanes 130 thereby tending to deflect any debris or seaweed away from the scoop and acting to be self-cleaning.

When the operator wishes to throttle or reverse the boat, the reversing gate is dropped over the bell housing, thus diverting all of the pump exhaust through the pair of nozzles formed in the nipples 158, 160 threadably received in the exhaust outlets 154, 156. Depending on the output of the pump, the boat speed may merely be stopped or upon application of more power to the impeller shaft, the amount of water directed through the nozzles may be increased sufficiently to cause the water vehicle to be reversed in direction.

The reversing gate can be used as a throttling means by fully or partially dropping the gate across the open end of the bell housing 42. In this manner, the gate can be used to completely negate the thrust power developed by the jet stream of water or any portion thereof, in addition to completely reversing the thrust being developed by the jet stream of water emitted from the pump. In this manner, both the throttle on the prime mover for the power device and the position of the gate reversing mechanism can be used to alter the speed of the craft.

Although a specific embodiment of the invention has been shown and described, it will be understood, of course, that it is only illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined in the appended claims.

I claim:

1. An inlet structure for water pump apparatus used to propel a boat comprising: a housing body adapted to receive a water pump, an inlet scoop attached to said housing body, and a collar in sealing engagement between the housing body and scoop whereby collars of different heights may be interposed between the housing body and scoop for operation on different size boats.

2. A water-jet propulsion unit for a boat comprising: a hollow housing having an inlet and an outlet, a pump rotatively mounted in said housing in juxtaposition with the outlet, an inducer rotatively mounted adjacent to the pump for purposes of forcing water into the pump, a gate pivotally mounted on the housing and having a shape mating with the housing outlet, a pair of nozzles on the housing for directing water downwardly and forwardly to reverse the direction of thrust imparted to the boat from the Water-jet produced by said pump, said housing inlet having a streamline shape for reducing drag, and a plurality of vanes positioned within the inlet for diverting water into the housing and to the inducer, whereby the water may be scooped into the housing inlet, forced by the inducer through the pump, and thereafter diverted downwardly by the gate into the nozzles producing a thrust to propel the boat in the reverse direction.

3. In a water-jet propulsion unit for providing thrust power to a watercraft from a jet stream of water, a water scoop adapted to direct water into the propulsion unit as the watercraft travels across a body of water, said water scoop comprising a housing having an inlet for receiving water, a plurality of vanes disposed in spaced relation within said housing at the inlet thereof, a plurality of spaced flexible elongated members attached at their forward ends to said housing at a leading portion thereof, said flexible elongated members being normally spaced below said vanes and extending across the inlet in substantially outwardly disposed relationship thereto, said vanes and said flexible elongated members being positioned at right angles to each other, the rearward ends of said flexible elongated members being freely movable, and said flexible elongated members being flexible about their forward end portions in response to the flow of water into the inlet of said housing so as to move toward and away from said vanes to brush thereagainst for deflecting debris away from the inlet and for dislodging debris from said vanes.

4. In a water-jet propulsion unit as defined in claim 3, wherein the leading portion of said housing to which the forward ends of said flexible elongated members are attached comprises a forwardly extending nose defining the forward portion of the inlet.

5. A water-jet propulsion unit for providing thrust power to a watercraft from a jet stream of water, said water-jet propulsion unit comprising a housing having an outlet at its rear end, a gate, means mounting said gate on said housing for pivotable movement between positions opening and closing the outlet of said housing,

means normally retaining said gate in a position such that the outlet of said housing is open, means operably associated with said housing for directing water into said housing as the watercraft travels across a body of water, pump means rotatively mounted within said housing for discharging Water through the outlet of said housing to develop forward thrust for the watercraft, a pair of nipples rotatively mounted on said housing and extending forwardly of the rear end of said housing on opposite sides thereof, each of said nipples having a nozzle in communication with the interior of said housing, the water acted upon by said pump means being diverted so as to be discharged from said housing through the nozzles of said nipples when said gate is pivoted to the position closing the outlet of said housing to reverse the direction of the thrust imparted to the watercraft, and the nozzle of each of said nipples being canted with respect to the axis of rotation thereof, whereby the angle at which the water may be discharged from said housing through the nozzles of said nipples is adjustable.

References Cited by the Examiner UNITED STATES PATENTS 1,620,129 3/27 Peterson 115-42 2,860,594 11/58 Kiekhaefer 115-17 3,007,305 11/61 Hamilton 115-14 3,035,409 5/62 Pifer -3555 X 3,040,695 6/62 Austin 115-14 3,046,735 7/62 Burgin 60-3555 3,082,732 3/63 Stallman 60-3555 X 3,083,530 4/63 Spence 60-3555 3,102,389 9/63 Pedersen et a1 60-3554 3,116,602 1/64 Dahle 60-3554 FOREIGN PATENTS 968,948 5/50 France.

716,381 10/54 Great Britain.

866,033 4/ 61 Great Britain.

168,333 8/34 Switzerland.

OTHER REFERENCES Robberson: Wet Jet Propulsion, Yachting Magazine, vol. 106, No. 5, pages -71, November 1959.

JULIUS E. WEST, Primary Examiner.

EDGAR W. GEOGHEGAN, Examiner. 

1. AN INLET STRUCTURE FOR WATER PUMP APPARATUS USED TO PROPEL A BOAT COMPRISING: A HOUSING BODY ADAPTED TO RECEIVE A WATER PUMP, AN INLET SCOOP ATTACHED TO SAID HOUSING BODY, AND A COLLAR IN SEALING ENGAGEMENT BETWEEN THE HOUSING BODY AND SCOOP WHEREBY COLLARS OF DIFFERENT HEIGHTS MAY BE INTERPOSED BETWEEN THE HOUSING BODY AND SCOOP FOR OPERATION ON DIFFERENT SIZE BOATS. 